Flask tutorial - 404 Not Found

Question

I just finished the Flask basic tutorial (here) and even though I\'ve done completed every step, when I am trying

python flaskr.py

what I get

Answer 1

Happened to me also while following Flask Application Setup here . The error was gone after appending a trailing slash at the end of the route.

@app.route('/hello')
    def hello():
        return 'Hello, World!'

was changed to

@app.route('/hello/')
    def hello():
        return 'Hello, World!'

and the problem was solved. Hope it helps for anyone who is searching for a problem like this.